The Silver Sword is a realistic novel about war that depends heavily on description for its literary effect. Because the setting of war-torn Europe shapes the children's experiences, Serraillier gives detailed and vivid descriptions of the ravaged countries and of the hardships the children endure. The role these problems play in building the children's characters is revealed several times by biblical parallels. Ruth tells Bible stories to the children in her school, and their favorite is the one which most inspires her as well: Daniel in the lions' den. She sees the hardships she faces every day as the lions, and she believes that if she is patient arid trusting like Daniel, she too will be delivered. Switzerland, as the children's destination, becomes the promised land that they reach after long wandering in the desert of the war.

The silver sword itself provides a recurring symbol of hope. The only vestige of the Balickis' home, the sword symbolizes the family's unity before the war. Joseph offers the sword to Jan as a pledge, and through Jan the sword serves as the crucial connection between Joseph and his children. It inspires Ruth to undertake the journey to look for her parents, and it spurs the children on as they travel. When the sword gets left behind at the Wolffs' farm, the children's luck changes for the worse; when the sword is returned, it cuts through the red tape of Swiss immigration and leads to the children's reunion with their parents. Jan firmly believes that the sword is responsible for the group's survival in the storm on the lake at the climax of the book. When his treasure box, symbolizing all the secrets of his past, finally sinks to the bottom of the lake, the sword alone remains, hanging from a string around his neck. He offers it, the most precious of his treasures, to Joseph's wife, Margrit, if she will be his mother. And so the pledge between Joseph and Jan is redeemed, and the sword brings the family back together.